Grain towers, or elevators, are widely used for storage of grain and it is necessary to aerate the grain stored therein. To this end, it has been known to provide grain elevators with air blowers and ancillary equipment to flow air from the bottom of the elevator upward through the grain therein and out the top of the elevator. A common prior system provides an air moving device outside the elevator structure with the air being introduced through a pipe extending through the sidewall of the elevator, the pipe branching off into smaller pipes in a "Y", or star, fashion in the grain compartment of the elevator, with perforations in the pipes for leaking the air into the grain compartment. Such prior system has not been entirely satisfactory.
A subsequent prior structure makes use of the fact that most grain elevators are not simply hollow cylinders with a base slab and a roof, but instead normally also include a floor about five or six feet above the base slab, with mechanism such as a grain conveyor being located between the floor and base slab and the grain being stored only above the floor overlying the lower compartment. That prior aeration system provides parallel walls dividing the lower compartment into three chambers, namely a central hallway and two outer chambers flanking same. Moreover, the floor is fabricated as a monolithic mass having numerous slots each covered with plates having substantial numbers of small perforations therethrough, such slots occupying the portion of the floor overlying the two outer chambers. Fans mounted on the outer peripheral surface of the grain elevator each force air under low pressure directly into the aforementioned two outside chambers, such air passing through the perforated floor and rising through the grain thereabove to aerate same.
The latter system, developed by Applicant, has been found to satisfactorily aerate grain in the tower or elevator. However, such system, in common with the earlier prior art system first described above, have a characteristic which in some locations is a substantial disadvantage. Particularly, the fans which supply air to the elevator in these prior structures are located on the exterior of the peripheral wall of the elevator. On an elevator of substantial size there would ordinarily be four of these fans mounted in circumferentially spaced relation on the outer peripheral surface of the elevator near the ground. The fan units are of large size and air flow capacity and tend to be very noisy. In certain locations, complaints from neighbors have caused the elevator owner to mount the fans largely on the side of the elevator away from nearby houses. This positioning will tend to reduce somewhat the noise radiated to houses on the blank side of the elevator, but even to these the noise still may be at an offensive level. Moreover, such concentration of fans on one side of the elevator would, of course, be of no help where nearby neighbors face several sides of the elevator or where adjacent buildings or other structures tend to reflect noise toward neighbors on the blank side of the elevator.